Method of molding a tire
This invention provides a method to hold tire reinforcements such as plies, belts and beads in place within a tire molding cavity while liquid elastomer surrounds the reinforcements, fills the tire mold and solidifies.
Application Ser. No. 10/674,989 filed Sep. 30, 2003—titled Reinforced Liquid Elastomer Tire Manufacturing Method and Apparatus for Manufacture, Frederick F. Vannan
BACKGROUNDA tire utilizes reinforcement components such as plies, belts, and beads to control tire size and shape and to hold it on a wheel. Traditional rubber tires are assembled on a building drum by laminating strips of rubber and rubber coated reinforcement. The rubber coating on the reinforcements is solid and sticky and un-vulcanized which allows it to control distance between reinforcements and to hold reinforcements in place until the vulcanization reaction can be completed.
Conventional rubber tires have manufacturing and performance problems associated with laminating one green and un-vulcanized component on top of another. The biggest problem is air entrapped between laminates and at ends of laminates. This entrapped air can cause a manufacturing defect in the cured, vulcanized, tire called a “blow”, which is an air bubble entrapped within the cured tire. A small blow which is not caught during tire inspection can become larger during service allowing structural components to separate and generate heat from friction between the separated components. This separation and heat can cause tire failure which is sometimes catastrophic.
The liquid elastomer tires of this invention are not assembled by laminating one elastomeric strip upon another. Instead, the tires of this invention have their reinforcements—plies, belts and beads—assembled and liquid elastomer poured or injected around them. There is no entrapped air within the finished tire structure and, therefore, no blows or separations in service.
SUMMARY OF INVENTIONThis invention provides a method to hold tire reinforcements in place within a tire mold cavity while liquid elastomer fills the mold cavity and solidifies.
This method utilizes at least partially solidified elastomer to hold ply and belt cords or cables together at specified angles during the tire assembly and elastomer molding processes. At least partially solidified elastomer is also used to position reinforcing components one to another and relative to the mold and internal core while the liquid elastomer fills the mold and solidifies.
The, at least partially solidified, elastomeric spacers have a high degree of adhesion to the reinforcements and to the liquid elastomer around them. The elastomeric spacers support the ply and control the distance between the ply and core and other plies and ply endings.
The elastomeric spacers support each belt and control the distance between first belt and ply and between belts.
The elastomeric spacers support each bead and control the distance between the beads and ply. These spacers also position the beads relative to the mold and core.
The elastomeric spacers support the overlay and control the distance between the overlay and top belt.
Elastomeric spacers 2 are attached to ply 1 and support it on core 12. Elastomeric spacers 4 support the first belt 3 and control spacing between belt 3 and ply 1. Elastomeric spacers 6 support the second belt 5 and control spacing between belt 5 and belt 3. Elastomeric spacers 8 support overlay 7 and control spacing between 7 and belt 5.
The beads 9 in
Individual ply cords 15, in
A circumferential cutter 21 in
Individual belt cords 25, in
A circumferential cutter 36 in
The sizes, shapes and numbers of elastomeric spacers and supports utilized in the ply band 22 in
Claims
1. Method of molding a tire, the method comprising: providing reinforcements of plies having endings, belt cords or cables, and beads, wherein the reinforcements having multiple at least partially solidified elastomer spacers attached thereto; providing beads that are encapsulated with at least partially solidified elastomer, wherein the ply endings are locked around the beads by another at least partially solidified elastomer spacer; assembling the reinforcements and the encapsulated beads in a mold cavity of an injection mold, the mold cavity has the shape of an entire tire, wherein the spacers position the reinforcements relative to one another, and the mold cavity surfaces in order to control the distances there between; and
- injecting an elastomer into the mold cavity to form the tire, wherein the injected elastomer surrounds the reinforcements, the at least partially solidified elastomer spacers, and the encapsulated beads, and the injected elastomer subsequently solidifies completing a reinforced tire ready for service.
2. The method of claim 1, wherein the elastomer spacers and the injected elastomer are polyurethane.
Type: Grant
Filed: Feb 11, 2005
Date of Patent: Dec 22, 2009
Patent Publication Number: 20060182829
Inventor: Frederick Forbes Vannan (Clinton, OH)
Primary Examiner: Edmund H. Lee
Application Number: 11/057,684
International Classification: B29C 45/14 (20060101);